Journal archives for February 2023

07 February, 2023

Observations in iNaturalist remain insufficient to draw the border between the two subspecies of the vicuna

@michalsloviak @michaelweymann @tonyrebelo @jwidness @diegoalmendras @geichhorn

Please see:

Please also see my own recent Post about the vicuna (

The two subspecies of the vicuna (Vicugna vicugna) differ as follows.

The northern subspecies, Vicugna vicugna mensalis, possesses a conspicuous tract of pale pelage on and around the chest, with the whitish hairs on the chest itself being noticeably longer than those anywhere else on the figure. Please see the third photo in

The southern subspecies, Vicugna vicugna vicugna, instead possesses a broad tract of fairly pale (but not particularly conspicuous) pelage on the posterior flanks, extending up to the level of the ileum (hip), as shown in

One of the puzzling aspects of the vicuna is that there is no obvious geographical barrier between the two subspecies. Instead, the distinction seems to be mainly latitudinal, within the endorheic region of the altiplano (

There are now more than a thousand observations of the vicuna in iNaturalist, offering the prospect of locating the subspecies-border precisely.

Today, I scrutinised the observations, but failed to locate this border satisfactorily.

This failure was because

  • many of the observations in the region concerned are too unclear, owing to photographic problems of distance and illumination, and
  • those photos that do clearly show the colouration present a confusing geographical pattern, at a small scale.

Just north of a north-south gap in the observations: is identifiable as subspecies mensalis.

The first observation south of this gap is:, which is identifiable as subspecies vicugna.

This suggests that the subspecies-border lies at the latitude of Salinas de Garci Mendoza (, viz. 19 degrees 38 minutes South.


An observation in this general area showing subspecies vicugna is This is at 20 degrees 31 minutes South.

So, the above observations collectively indicate that the subspecies-border lies at 20 degrees South - which happens to be the latitude of the largest salina on Earth ( - or slightly farther south.

This differs considerably from, in which Wheeler (2012) gives the crucial latitude as only 18 degrees South.

However, precise delineation remains elusive, for now.

We need

  • more, and clearer, photographs around the latitude of 20 degrees South, and
  • more information on possible small-scale translocations made by those conserving the species for its valuable wool, but not necessarily respecting the subspecies-distinction.
Posted on 07 February, 2023 16:26 by milewski milewski | 3 comments | Leave a comment

More evidence that the Indian peafowl is unnattractive as prey to the leopard

Posted on 07 February, 2023 18:21 by milewski milewski | 0 comments | Leave a comment

08 February, 2023

Drymaplaneta semivitta, a lovable indigenous cockroach commensal in human homes in Perth, Western Australia

In my house and garden in inner-city suburban Perth, Western Australia, I have long had a friendly policy towards weeds and commensals. As far as possible, I allow 'wildlife' to share my living space, even indoors.

I can therefore report, based on at least three decades of experience, on the topic of the indigenous cockroach Drymaplaneta semivitta ( and

This species is closely related to Drymaplaneta communis (, which inhabits the largest Australian cities, in the southeast of the continent.

Drymaplaneta semivitta is a flightless cockroach with a body about 2.7 cm long. It is smaller-bodied than the non-indigenous, and far more abundant and gregarious, Periplaneta americana ( and,150%20young%20in%20her%20lifetime.) and Blatella germanica (

It is also slow-moving and confiding, hardly reacting to human approach even in warm weather. It shows the same disarming fearlessness towards the human species as do two indigenous birds common in my garden, namely Rhipidura leucophrys ( and Grallina cyanoleuca (

Drymaplaneta semivitta is remarkably constant as a presence in my house and garden, being encountered as individuals (never in groups) behind wall-murals, in piles of paper, under bark the on trees, and in coarse mulch. It climbs smooth walls easily. It seems naturally scansorial, rather than terrestrial. It lacks defence-postures or -displays, and flees reluctantly/sluggishly.

In my experience, it has shown no noticeable seasonal variation in activity or breeding. This implies slow and steady metabolism, growth, and reproduction.

I have never felt any impulse to kill this species, even in my kitchen. I find its demeanour on discovery, which is confiding, unexcitable, and 'tame', to be endearing. It is silent and seemingly odourless. The only nuisance that I have noticed is the fecal specks that it leaves on the wall behind picture-frames

If one considers both body-size multiplied by the number of individuals per unit area, D. semivitta is the major indigenous invertebrate - and indeed non-human animal of any sort - inhabiting the interior of my house.

The gecko Christinus marmoratus ( is commensal in Perth, and is at least three-fold more massive than D. semivitta.

However, it remains at the outside of the building, is relatively scarce (with an average of only a few encounters per year, usually when some object such as a brick-pile is disturbed), and seems never actually to enter my house. The lizard is far more secretive, far less commensal, and far less numerous than the indigenous cockroach.

Posted on 08 February, 2023 20:34 by milewski milewski | 10 comments | Leave a comment

13 February, 2023

Ungulates with short vs long necks: how do their mouths reach the ground?

Alces alces:

Lama guanicoe:

Posted on 13 February, 2023 22:20 by milewski milewski | 17 comments | Leave a comment

Variation among ungulates in flexibility of fetlock joint

The following photos of Rangifer tarandus tarandus ( provide food for thought: and

The following shows that the false-hooves (dewclaws) touch the ground even during walking:

However, they do not touch the ground during standing: and

This suggests that, in Rangifer tarandus, the false-hooves (dewclaws) tend to touch the ground even when walking on firm surfaces.

The following shows that, in Alces alces, the false-hooves likewise touch the ground during trotting on a firm surface:

However, in the case of A, alces, thenfalse-hovves remain clear of the ground during walking:

Alces alces:

Bubalus carabanensis:

Posted on 13 February, 2023 22:46 by milewski milewski | 22 comments | Leave a comment

14 February, 2023

Subtle and multifaceted adaptive colouration in the largest wild ruminant in South America: the guanaco (Lama guanicoe), part 1

@tonyrebelo @jeremygilmore @michaelweymann @chewitt1 @diegoalmendras @jwidness @maxallen @paradoxornithidae @dinofelis @beartracker @oviscanadensis_connerties @aguilita @minnesota @jorgebrito @juanmauriciocontreras @matthewinabinett @tandala @birdernaturalist @goncrisdi @frangtaboas @jaddesi @josh_vandermeulen @attila21 @anttanager @diegoeseolivera @estebansuarez_r @jakob @davidbygott @dejong @capracornelius @michalsloviak @pinawapt @aparrot1 @martin_arregui @carita @kristofz @hardinglee @markconboy @apeterlongo @minnesota @dyeany2

(For my account of the vicuna, please see

The colouration in the guanaco (Lama guanicoe, is simple in the sense that it does not vary with sex or age. Males, females, juveniles, and infants all share the same colouration.

However, the patterns are difficult to describe, because

  • the species is neither plain-coloured nor conspicuously patterned in an unambivalent and consistent way,
  • subspecies remain poorly-defined, and
  • there is considerable variation among individuals and populations, beyond a recognisable north-south cline.

Conspicuous features of adaptive colouration, in mammals including the guanaco, may be noticeably dark, noticeably pale, or both together in the form of dark/pale contrast.


The following is a reminder of the degree of conspicuousness of a lateral bleeze: Eudorcas thomsoni

In the guanaco, the pale of the ventral surface of the torso extends too high on the flanks to function merely as countershading.

This is true particularly for the posterior flank, on which the depigmented tract almost reaches the back/rump ( and and and and and

An advantage of the placement of the pale tract on the posterior flank is that the feature is conspicuous not only in profile but also in

The following photo might not have been worth taking, were it not for the postulated lateral bleeze (

The following shows the maximal extent of pale on the flanks of the guanaco:

However, for the species overall, the feature in question does not necessarily qualify as a bleeze.

This is because some populations, particularly in Peru/northern Chile and northwestern Argentina, tend to lack the pale tract ( and and and and and and and and and and


The following is a reminder of the degree conspicuousness of a facial bleeze: Damaliscus oygargus phillipsi

A facial flag is less conspicuous than the above, but becomes conspicuousness when moved.

(For a description of laryngeal and auricular flags, please see

The head of the guanaco tends to have dark aspects and pale aspects, in some cases in combination.

The face of the guanaco, unlike that of the vicuna (Vicugna vicugna), tends to be somewhat dark ( and and and and

Furthermore, there tends to be a pale, possibly sheeny streak from the crook of the throat to, and including, the ear pinnae ( and and and and and and and and

Of thousands of photos of the guanaco on the Web, the following shows a hypothetical facial/laryngeal flag most clearly (

However, the darkness on the face is one of the most variable aspects of colouration in the guanaco, both regionally and individually. Furthermore, even more than in the vicuna (, the pallor on the side of the posterior part of the face is so small-scale ( that its effectiveness as a conspicuous feature is questionable.


Please see

The inner surfaces of the legs are so extensively and uniformly whitish in the guanaco that this far exceeds countershading ( and and and

This suggests that the whitish inner surface of the upper hindleg, in particular, functions as a flag during walking ( and


The following is a reminder of the degree of conspicuousness of a posterior bleeze (Dama dama

In the guanaco, the buttocks, and the posterior surfaces of the forelegs, tend to be pale ( and

This is partly because the short pelage as well as the associated visible skin of the buttocks are depigmented - unlike the somewhat pigmented bare skin of the perineal area, around anus and vulva (see second photo in

Furthermore, in those populations and individuals in which the pelage on the tail is dark, there is some degree of dark/pale contrast on the posterior aspect of the figure (

The pattern on the buttocks of the guanaco is usually more conspicuous than that in the vicuna (

However, it is questionable whether this qualifies as a bleeze, even in the case of the guanaco.

This is because


The following us a reminder of the degree of conspicuousness of a frontal bleeze: Vicugna vicugna mensalis

In the guanaco, there are two features, on the front of the figure, that potentially function as large-scale advertisement (

These are

A difference between the guanaco and the vicuna is that the anterior surface of the neck is pale only in the former species.

This tends to make the figure conspicuous, because the upright orientation of the long neck of the guanaco ( precludes this pale pelage functioning as countershading.

Furthermore, the pale pelage in question is long enough that the conspicuousness applies also under backlit illumination ( and and and and and and

However, it is questionable whether the guanaco qualifies as possessing a frontal bleeze.

This is because


An intriguing aspect of the anatomy of the guanaco, located at the abdomen ('inguinal'), near the elbow ('axillary'), on the buttocks, and on the ventral surface of the tail, is

  • the sharp differentiation of long pelage from apparently bare skin, and
  • the difference between the pale skin of groin, buttocks, and tail and the dark skin of the perineum.

The main function of the pale, apparently bare skin seems to be thermoregulation, rather than display by means of colouration.

When the animal stands under normal conditions, the panels of apparently bare skin are 'closed', by virtue of

However, when the slight hunching of the torso is relaxed, what becomes visible is the clear distinction between the ventral pelage and the apparently bare skin,

These apparently bare surfaces function as regulate body heat via perspiration ( and and and and radiation. In cold weather, the apparently bare panels can be covered, mainly by postural adjustments including the 'clamping' of the tail.

Few ungulates on Earth possess this mechanism, which may be related to the unusually narrow 'waist' of camelids ( and

At first glance, there is little remarkable about the pale tract on the abdomen in the following ( and

However, on closer scrutiny it can be seen that there is a considerable area of pale, apparently bare skin. There is another, similar but smaller, patch of pale, apparently bare skin just posterior to the elbow.

From the viewpoint of colouration:
A remarkable aspect of this anatomical configuration is that the skin is so depigmented that, even when maximally exposed, it does not detract from the conspicuous pallor of the flanks ( and and and and

to be continued in

Posted on 14 February, 2023 16:22 by milewski milewski | 37 comments | Leave a comment

16 February, 2023

18 February, 2023

Subtle and multifaceted adaptive colouration in the largest wild ruminant in South America: the guanaco (Lama guanicoe), part 2

...continued from

In part 1, I have described the larger-scale features of adaptive colouration in the guanaco. Here, I describe the smaller-scale features, followed by an overall discussion.


The following is a reminder of how conspicuous a caudal flag can be: Odocoileus virginianus

The tail of the guanaco tends to be somewhat dark (

It is also habitually raised, to varying degrees and in various circumstances ( and and and and

However, there is much individual/regional variation in the size and tone of the tail.

Furthermore, the bare skin on the ventral surface of the tail, visible when the tail is raised, is inconspicuously pale ( and and and

The following shows the maximum size and darkness of the tail (

The following show the minimum size and darkness of the tail ( and and and and and

Overall, the case for a caudal flag is weak. The tail certainly has functions in signalling/self-advertisement in the guanaco. However, what is ambivalent is the degree to which colouration plays a role in this.


The following is a reminder of how conspicuous a pedal flag can be: Boselaphus tragocamelus

The lower legs of the guanaco may be pale, in a way that is potentially conspicuous, particularly when the limbs move ( and and and and

However, this is inconsistent among individuals and populations ( and and and

Because the feet do not have conspicuous colouration in most individuals/regions, I doubt that the guanaco qualifies as possessing a pedal flag.


There seems to be a sheen effect on the posterior surface of the ear pinnae in the guanaco ( and and and and

The anterior surface of the ear pinnae is also conspicuously pale in some views ( and and

In northern populations, the ear pinnae in some individuals are dark ( and

However, the conspicuousness of the ear pinnae is limited, owing to their small size ( and and and

Populations in/near the Atacama Desert may have the largest ear pinnae ( and

A case can be made that the colouration of the ear pinnae in the guanaco qualifies as an auricular semet, expressing emotion in close-range social (intraspecific) interactions ( and However, this is undermined by the regional occurrence of individuals in which the ear pinnae are as dark as the rest of the head.


The maximum similarity in colouration between the guanaco ( and and the vicuna ( is considerable.

It is testimony to the similarity in colouration between the guanaco and V. v. vicugna that dozens of photos of the latter are mislabelled as the former on the Web.

Overall, the most significant, and least ambivalent, of the features of adaptive colouration in the guanaco is the pale of the posterior flank ( and and and and

This feature, as in the vicuna, is 'caleonic' in origin (

The postulated lateral bleeze of the guanaco (which functions also anterio- and posteriolaterally) resembles a feature of conspicuous colouration in the southern, nominate subspecies of the vicuna, viz., V. v. vicugna ( and and and and and and

However, even this caleonic, relatively large-scale feature is too inconsistent for the guanaco, as a species overall, to qualify as possessing unambivalently conspicuous colouration.

I hesitate to invoke subspecies in the case of the guanaco.

However, my finding is that the northern populations have the least conspicuous colouration, with the possible exception of a dark head ( and and and and and and

Posted on 18 February, 2023 01:23 by milewski milewski | 3 comments | Leave a comment

Doubt about the taxonomic status of subspecies in both of the wild camelids of South America

@michaelweymann @michalsloviak @tonyrebelo @geichhorn @jwidness @jakob

There are two species of wild camelids in South America, namely the vicuna (Vicugna vicugna, and the guanaco (Lama guanicoe,

In both,

  • there is sexual monomorphism, with so little difference in appearance between male and female that the sexes are hard to distinguish in the field,
  • the intraspecific variation is mainly latitudinal (north-south),
  • body size is considerably smaller in northern than in southern forms, and
  • the distributions are wide enough that subspecies have been postulated.

However, in both species, the question of subspeciation remains somewhat puzzling and unresolved.

In the case of the vicuna, there is no problem recognising the two subspecies, which look so different that raising them to the status of different species (Groves and Grubb 2011) seems reasonable.

What has not previously been pointed out is that the two subspecies differ categorically in a way.

The northern subspecies has conspicuous colouration overall, whereas the southern subspecies does not ( Furthermore, confusion of identity, in which photos of the vicuna on the Web are mislabelled as the guanaco, occurs only in the case of V. v. vicugna.

However, the puzzle is how the two subspecies have remained distinct, despite the lack of a geographical barrier between them.

Vicugna vicugna vicugna and Vicugna vicugna mensalis live in similar landscapes, and under similarly extreme (high-altitude) climates. One merely replaces the other on a south-north basis - so abruptly that there seems to be no zone of natural intergradation.

In the case of the guanaco,

  • the northern and southern forms are as not as consistently different as in the case of the vicuna - despite the greater latitudinal span involved, and
  • there is more individual variation, within any given population, than in the case of the vicuna.

(What has not previously been pointed out is that the vicuna is one of the least individually variable of ungulates, all adult members within each subspecies appearing virtually identical once the effects of intermittent wool-shearing by humans are taken into account.)

In the guanaco the intraspecific variation seems too patchy and irregular to allow identification of subspecies on the basis of either appearance or region. A clinal, as opposed to subspecific, system of variation seems plausible.

The following is a closer scrutiny of subspecific variation in the two species.


The northern subspecies of the vicuna, viz. Vicugna vicugna mensalis, is easily recognised by virtue of its frontal bleeze, centred on the chest:

The pale pelage in the southern subspecies of the vicuna, viz. Vicugna vicugna vicugna, emphasises the hips instead of the chest. However, it is not particularly conspicuous in either of these parts of the body: (mislabelled on the Web) (mislabelled on the Web) (mislabelled on the Web) (mislabelled on the Web) (mislabelled on the Web) (mislabelled on the Web) (mislabelled on the Web) (mislabelled on the Web) (mislabelled on the Web)


In the case of the guanaco:

Previous descriptions, in the literature, of the difference between northern and southern forms of the guanaco ( seem inept/incomplete/misleading.

This because

  • it has been claimed that the northernmost subspecies, namely Lama guanicoe cacsilensis, tends to be relatively pale - which is not borne out by the many photos on the Web, from Peru and northern Chile,
  • a major point has been overlooked, viz. that the pale tracts on the posterior flanks and on the buttocks are poorly-developed, and
  • a minor point has been overlooked, viz. that the dark on the head extends relatively far to the posterior, including the ear pinnae in some individuals.

The following are the northernmost 44 observations of the guanaco in iNaturalist, west of the Andes, all of which would presumably fall within subspecies cacsilensis: (apparently hybridised with Lama glama)

What these photos reveal is a relatively uniform colouration, with a ground-colour that is not noticeably pale in most individuals. In these populations, most of the pale features of the species are relatively poorly-developed, disqualifying what I have referred to as

  • a lateral bleeze,
  • a frontal bleeze,
  • a posterior bleeze/flag, and
  • a laryngeal flag.

Furthermore, the head is consistently and extensively rather dark, the darkness extending to the ear pinnae in some individuals.

At the other (southern) extreme of the distribution of the guanaco lies the island of Tierra del Fuego (

The many observations in iNaturalist from Tierra del Fuego can be seen in These all fall within the nominate subspecies, guanicoe.

Within these sets of photos, the clearest comparison is between



This confirms that the main difference between the northern and southern forms is the extension of the ventral pale pelage on to the flanks (constituting a lateral bleeze) in the latter.

Although this difference seems obvious, I have yet to see it pointed out in the literature. This omission may be partly because terms such as 'blaze', 'bles', and 'bleeze' are too specialised to be applied to general descriptions. However, by stating that it is the northern form that is the paler overall, previous authors have, in a sense, inverted the real relationship.

Although adapted to arid to semi-arid climates, the northern form of the guanaco is not pallid in the way so familiar in mammals and birds of deserts. It is, instead, better-described as relatively plain-coloured for its species.

Based on the consistent difference between northern and southern forms of the guanaco in the absence/presence of a lateral bleeze, I would have no objection to recognising these as valid subspecies, namely cacsilensis and nominate guanicoe. However, it remains possible that the variation is clinal (on a latitudinal basis), rather than subspecific.

Furthermore, it remains unclear how the remaining two postulated subspecies, namely voglii (Bolivia and northwestern Argentina) and huanacus (central Chile), relate to the colouration illustrated here.

It would make sense for voglii (east of the Andes) to differ from huanacus (west of the Andes), because they are separated by a formidable geographical barrier. However, clear differences among the three forms, cacsilensis, voglii (, and huanacus (, have yet to be demonstrated.

A strong case can be made - based partly on the lack of any cline/intergradation - for the recognition of Vicugna vicugna vicugna as a species separate from what is currently regarded as subspecies mensalis. It is, therefore, ironic that this relatively plain-coloured southern form of the vicuna is not only seldom appreciated for its distinctiveness, but it is frequently misidentified as the northern, relatively plain-coloured form of the guanaco.

This confusion, which is an embarrassment on the Web, results partly from the fact that both V. v. vicugna (high altitudes) and L. g. cacsilensis (low altitudes) occur in the Atacama region (in a sense broader than the low-altitude desert,

Posted on 18 February, 2023 08:11 by milewski milewski | 28 comments | Leave a comment

24 February, 2023

The springbok (Antidorcas marsupialis) seems to qualify as possessing a facial flag, but not a caudal flag


Also see and

Bigalke (1972,, on page 336, states, under the heading "HEAD TOSSING":

"springbok often toss the head as they move off, commonly at a fast trot, when alarmed. The movement is pronounced, the head being lowered to near the ground and raised again repeatedly. It appears in other gaits as well...Head tossing is an important element of the stott and also appears in the proud trot."

Has this behaviour ever been photographed or filmed, beyond inadvertent coverage as part of stotting? (


From the viewpoint of adaptive colouration, I hypothesise that the whitish pelage, covering most of the face in adults of the springbok, constitutes a facial flag (a term I have recently coined, 50 years after this paper by Bigalke was published).

All flags, in the sense of adaptive colouration in mammals, are by definition activated by motion. In this case, the activation is partly by means of head-tossing, as described by Bigalke.

The facial flag of the springbok has an ontogenetic component, being absent at birth, and fully-developed in adulthood.

The fawn-coloured markings on the face in infants and juveniles ( tend to disappear in adulthood, in both sexes.

The following are particularly clear illustrations of the difference in facial colouration between infants and their mothers:

First photo in

The following show the progressive loss of the fawn (ground-colour) from the face, with the age of the individual:



Juvenile just after horns appear:

Adult female:

Adult male:


On page 335 of the same publication, Bigalke (1972) states:

"Walther points out that the tail of all gazelles is an extremely mobile organ. In the springbok, the tail is moved from side to side incessantly while the animals feed or walk about. Tense situations, as for example when a resting herd is disturbed and the animals rise and watch the intruder, also produce active tail wagging. In flight, on the other hand, the tail is pressed up against the body between the haunches, as in Grant's gazelle (Walther 1968)."

The following hardly support Bigalke's observation that the tail is routinely wagged during walking:

The following do support Bigalke's observations, but show how inconspicuous the tail is, even in motion:

In terms of adaptive colouration, a caudal flag consists of a pattern of dark, pale, or dark/pale contrast, on and adjacent to the tail, that is not necessarily conspicuous in the stationary figure, but becomes conspicuous in motion, even at some distance.

The springbok differs from most other gazelles in that its tail

Therefore, even when the springbok wags its tail in normal activity, and in mild alarm, this does not necessarily mean that this signal is significantly amplified by the colouration of the tail. A good example of such amplification is instead seen in the goitred gazelle (Gazella subgutturosa), in which the pattern is far more graphic than in the springbok (

The following shows the maximum development of the dark tassel of the tail in the springbok ( However, once again, contrary to Bigalke, it is not activated during routine walking.

My findings, therefore, are that the springbok

  • qualifies as possessing a facial flag (in adolescents and adults of both sexes, not in infants or juveniles), but
  • does not qualify as possessing a caudal flag (owing to the tail being too slight, too inflexible, and too inert for the combination of whitish tail-stalk and dark tassel to add much to the conspicuousness of the figure).
Posted on 24 February, 2023 11:56 by milewski milewski | 6 comments | Leave a comment